WEBT003 (Talk)

L4-Linux Based System as a Platform for EPICS
iocCore

J. Odagiri, N. Yamamoto and T. Katoh

The EPICS Input / Output Controller (IOC) core-program, iocCore [1], is now
portable to multi-platforms. The Linux operating system, among them, seems to be a
promising candidate for a platform to run iocCore, considering the recent high
appreciation in desktop and server use as well as control fields. The Linux kernel,
however, is not suitable for time-critical applications since it responds to external
events with unpredictable latency. We summarize known causes of the latency, and then
discuss some of the different solutions for the problem in view of availability to
iocCore. As a possible alternative, we propose an approach that dispatches user level
processes by a real-time kernel aiming at consistency of availability with predictable
responsiveness.